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Role of Polyelectrolytes in Crystallogenesis of Calcium Carbonate
Author(s) -
Jada Amane,
Jradi Khalil
Publication year - 2006
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200690011
Subject(s) - vaterite , calcite , calcium carbonate , polyelectrolyte , acicular , chemical engineering , crystallization , materials science , polymer , mineralogy , crystallography , aragonite , chemistry , composite material , microstructure , engineering
The effects anionic polyelectrolytes, having various molecular weights and repeating unit structures, on the crystallization of calcium carbonate in supersaturated solutions are studied. The induction times of the crystals grown in the presence of the polymers were optically evaluated; X‐ray diffraction and Scanning Electronic Microscopy (SEM) analyses were performed to determine, respectively, their crystalline structures and morphologies. The polyelectrolyte is found to lengthen the induction time and to reduce the size of CaCO 3 nanocrystallites, to an extent depending on the interaction efficiency between the polymer anionic repeating units and the calcium ions. Further, depending on their sizes and their crystalline structures (calcite, vaterite) the nanocrystallites aggregate and yield final calcium carbonate particles having various sizes and morphologies. The data indicate that nanocrystals having vaterite structure, as determined by X‐ray analysis, give spherical CaCO 3 final particles, while nanocrystals having calcite structure lead to either acicular or flower shapes of CaCO 3 final particles.